The present invention relates to the delivery of rizatriptan or zolmitriptan through an inhalation route. Specifically, it relates to aerosols containing rizatriptan or zolmitriptan that are used in inhalation therapy.
There are a number of compositions currently marketed for the treatment of migraine headaches. The compositions contain at least one active ingredient that provides for observed therapeutic effects. Among the active ingredients given in such anti-migraine compositions are rizatriptan and zolmitriptan.
It is desirable to provide a new route of administration for rizatriptan and zolmitriptan that rapidly produces peak plasma concentrations of the compounds. The provision of such a route is an object of the present invention.
New routes of administration for the compounds may increase the rate at which their peak plasma concentrations are reached. Such routes are provided herein.
The present invention relates to the delivery of rizatriptan or zolmitriptan through an inhalation route. Specifically, it relates to aerosols containing rizatritpan or zolmitriptan that are used in inhalation therapy.
In a composition aspect of the present invention, the aerosol comprises particles comprising at least 5 percent by weight of rizatriptan or zolmitriptan. Preferably, the particles comprise at least 10 percent by weight of rizatriptan or zolmitriptan. More preferably, the particles comprise at least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90 percent, 95 percent, 97 percent, 99 percent, 99.5 percent or 99.97 percent by weight of rizatriptan or zolmitriptan.
Typically, the aerosol has a mass of at least 10 xcexcg. Preferably, the aerosol has a mass of at least 100 xcexcg. More preferably, the aerosol has a mass of at least 200 xcexcg.
Typically, the particles comprise less than 10 percent by weight of rizatriptan or zolmitriptan degradation products. Preferably, the particles comprise less than 5 percent by weight of rizatriptan or zolmitriptan degradation products. More preferably, the particles comprise less than 2.5, 1, 0.5, 0.1 or 0.03 percent by weight of rizatriptan or zolmitriptan degradation products.
Typically, the particles comprise less than 90 percent by weight of water. Preferably, the particles comprise less than 80 percent by weight of water. More preferably, the particles comprise less than 70 percent, 60 percent, 50 percent, 40 percent, 30 percent, 20 percent, 10 percent, or 5 percent by weight of water.
Typically, at least 50 percent by weight of the aerosol is amorphous in form, wherein crystalline forms make up less than 50 percent by weight of the total aerosol weight, regardless of the nature of individual particles. Preferably, at least 75 percent by weight of the aerosol is amorphous in form. More preferably, at least 90 percent by weight of the aerosol is amorphous in form.
A solution of 10 mg rizatriptan in 1 mL diethyl ether was spread out in a thin layer on a 10 cmxc3x9715 cm sheet of aluminum foil. The diethyl ether was allowed to evaporate. Assuming a drug density of about 1 g/cc, the calculated thickness of the rizatriptan coating on the 150 cm2 aluminum solid support, after solvent evaporation, is about 0.7 microns. The coated aluminum foil sheet was inserted into a glass tube in a furnace (tube furnace). A glass wool plug was placed in the tube adjacent to the foil sheet, and an air flow of 2 L/min was applied. The furnace was heated to 250xc2x0 C. for 30 s to volatilize the coated rizatriptan and then was allowed to cool. The glass wool was extracted, and HPLC analysis of the collected material showed it to be at least 99% pure rizatriptan.
A solution of 11.3 mg rizatriptan in 200 xcexcL dichloromethane was spread out in a thin layer on the central portion of a 4 cmxc3x979 cm sheet of aluminum foil. The dichloromethane was allowed to evaporate. Assuming a drug density of about 1 g/cc, the calculated thickness of the rizatriptan thin layer on the 36 cm2 aluminum solid support, after solvent evaporation, is about 3.1 microns. The aluminum foil was wrapped around a 300 watt halogen tube, which was inserted into a T-shaped glass tube. One of the openings of the tube was sealed with a rubber stopper, another was loosely covered with the end of the halogen tube, and the third was connected to a 1 liter, 3-neck glass flask. The glass flask was further connected to a large piston capable of drawing 1.1 liters of air through the flask. Alternating current was run through the halogen bulb by application of 90 V using a variac connected to 110 V line power. Within 1 s, an aerosol appeared and was drawn into the 1 L flask by use of the piston, with collection of the aerosol terminated after 7 s. The aerosol was analyzed by connecting the 1 L flask to an eight-stage Andersen non-viable cascade impactor. Results are shown in table 1. MMAD of the collected aerosol was 1.2 microns with a geometric standard deviation of 1.7. Also shown in table 1 is the number of particles collected on the various stages of the cascade impactor, given by the mass collected on the stage divided by the mass of a typical particle trapped on that stage. The mass of a single particle of diameter D is given by the volume of the particle, xcfx80D3/6, multiplied by the density of the drug (taken to be 1 g/cm3). The inhalable aerosol particle density is the sum of the numbers of particles collected on impactor stages 3 to 8 divided by the collection volume of 1 L, giving an inhalable aerosol particle density of 3xc3x97107 particles/mL. The rate of inhalable aerosol particle formation is the sum of the numbers of particles collected on impactor stages 3 through 8 divided by the formation time of 7 s, giving a rate of inhalable aerosol particle formation of 5xc3x97109 particles/second.
A solution of 11.6 mg rizatriptan in 200 xcexcL dichloromethane was spread out in a thin layer on the central portion of a 4 cmxc3x979 cm sheet of aluminum foil. The dichloromethane was allowed to evaporate. Assuming a drug density of about 1 g/cc. the calculated thickness of the rizatriptan thin layer on the 36 cm2 aluminum solid support, after solvent evaporation, is about 3.2 microns. The aluminum foil was wrapped around a 300 watt halogen tube, which was inserted into a T-shaped glass tube. One of the openings of the tube was sealed with a rubber stopper, another was loosely covered with the end of the halogen tube, and the third was connected to a 1 liter, 3-neck glass flask. The glass flask was further connected to a large piston capable of drawing 1.1 liters of air through the flask. Alternating current was run through the halogen bulb by application of 90 V using a variac connected to 110 V line power. Within seconds, an aerosol appeared and was drawn into the 1 L flask by use of the piston, with formation of the aerosol terminated after 7 s. The aerosol was allowed to sediment onto the walls of the 1 L flask for approximately 30 minutes. The flask was then extracted with dichloromethane and the extract analyzed by HPLC with detection by light absorption at 225 nm. Comparison with standards containing known amounts of rizatriptan revealed that 3.2 mg of  greater than  99% pure rizatriptan had been collected in the flask, resulting in an aerosol drug mass density of 3.2 mg/L. The aluminum foil upon which the rizatriptan had previously been coated was weighed following the experiment. Of the 11.6 mg originally coated on the aluminum, all of the material was found to have aerosolized in the 7 s time period, implying a rate of drug aerosol formation of 1.7 mg/s.
Typically, where the particles comprise zolmitriptan, the particles comprise less than 5 percent by weight of didehydro zolmitriptan. Preferably, the particles comprise less than 2.5 percent by weight of didehydro zolmitriptan. More preferably, the particles comprise less than 1, 0.5, 0.1 or 0.03 percent by weight of didehydro zolmitriptan.
A solution of 9.8 mg zolmitriptan in 300 xcexcL dichloromethane was spread out in a thin layer on a 4 cmxc3x979 cm sheet of aluminum foil. The dichloromethane was allowed to evaporate. Assuming a drug density of about 1 g/cc, the calculated thickness of the zolmitriptan thin layer on the 36 cm2 aluminum solid support, after solvent evaporation, is about 2.7 microns. The aluminum foil was wrapped around a 300 watt halogen tube, which was inserted into a glass tube sealed at one end with a rubber stopper. Subjecting the bulb to one 15s, 60 v (variac) treatment afforded volatilized zolmitriptan on the glass tube walls. HPLC analysis of the collected material showed it to be at least 98% pure zolmitriptan. To obtain higher purity aerosols, one can coat a lesser amount of drug, yielding a thinner film to heat. A linear decrease in film thickness is associated with a linear decrease in impurities.
A solution of 3.2 mg zolmitriptan in 100 xcexcL methanol was spread out in a thin layer on the central portion of a 3.5 cmxc3x977 cm sheet of aluminum foil. The dichloromethane was allowed to evaporate. Assuming a drug density of about 1 g/cc. the calculated thickness of the zolmitriptan thin layer on the 24.5 cm2 aluminum solid support, after solvent evaporation, is about 1.3 microns, The aluminum foil was wrapped around a 300 watt halogen tube, which was inserted into a T-shaped glass tube. Both of the openings of the tube were left open and the third opening was connected to a 1 liter, 3-neck glass flask. The glass flask was further connected to a large piston capable of drawing 1.1 liters of air through the flask. Alternating current was run through the halogen bulb by application of 90 V using a variac connected to 110 V line power. Within 1 s, an aerosol appeared and was drawn into the 1 L flask by use of the piston, with collection of the aerosol terminated after 6 s. The aerosol was analyzed by connecting the 1 L flask to an eight-stage Andersen non-viable cascade impactor. Results are shown in table 1. MMAD of the collected aerosol was 0.7 microns with a geometric standard deviation of 3.3. Also shown in table 1 is the number of particles collected on the various stages of the cascade impactor, given by the mass collected on the stage divided by the mass of a typical particle trapped on that stage. The mass of a single particle of diameter D is given by the volume of the particle, xcfx80D3/6, multiplied by the density of the drug (taken to be 1 g/cm3). The inhalable aerosol particle density is the sum of the numbers of particles collected on impactor stages 3 to 8 divided by the collection volume of 1 L, giving an inhalable aerosol particle density of 4.9xc3x97107 particles/mL. The rate of inhalable aerosol particle formation is the sum of the numbers of particles collected on impactor stages 3 through 8 divided by the formation time of 6 s, giving a rate of inhalable aerosol particle formation of 8.1xc3x97109 particles/second.
A solution of 2.6 mg zolmitriptan in 100 xcexcL methanol was spread out in a thin layer on the central portion of a 3.5 cmxc3x977 cm sheet of aluminum foil. The dichloromethane was allowed to evaporate. Assuming a drug density of about 1 g/cc, the calculated thickness of the zolmitriptan thin layer on the 24.5 cm2 aluminum solid support, after solvent evaporation, is about 1.1 microns. The aluminum foil was wrapped around a 300 watt halogen tube, which was inserted into a T-shaped glass tube. Both of the openings of the tube were left open and the third opening was connected to a 1 liter, 3-neck glass flask. The glass flask was further connected to a large piston capable of drawing 1.1 liters of air through the flask. Alternating current was run through the halogen bulb by application of 90 V using a variac connected to 110 V line power. Within seconds, an aerosol appeared and was drawn into the 1 L flask by use of the piston, with formation of the aerosol terminated after 6 s. The aerosol was allowed to sediment onto the walls of the 1 L flask for approximately 30 minutes. The flask was then extracted with acetonitrile and the extract analyzed by HPLC with detection by light absorption at 225 nm. Comparison with standards containing known amounts of zolmitriptan revealed that 0.4 mg of  greater than  96% pure zolmitriptan had been collected in the flask, resulting in an aerosol drug mass density of 0.4 mg/L. The aluminum foil upon which the zolmitriptan had previously been coated was weighed following the experiment. Of the 2.6 mg originally coated on the aluminum, 1.5 mg of the material was found to have aerosolized in the 6 s time period, implying a rate of drug aerosol formation of 0.3 mg/s.
Typically, the geometric standard deviation around the mass median aerodynamic diameter of the aerosol particles is less than 3.5. Preferably, the geometric standard deviation is less than 3.0. More preferably, the geometric standard deviation is less than 2.5 or 2.0.
Typically, the aerosol is formed by heating a composition containing rizatriptan or zolmitriptan to form a vapor and subsequently allowing the vapor to condense into an aerosol.
In another composition aspect of the present invention, a dose form of an antimigraine compound is provided for the treatment of migraine, wherein the dose form comprises less than the typical oral dose of the antimigraine compound.
Typically, where the antimigraine compound is rizatriptan, the dose form comprises less than 4 mg of rizatriptan. Preferably, the dose form comprises less than 3.5 mg of rizatriptan. More preferably, the dose form comprises less than 3.0 or 2.5 mg of rizatriptan.
Typically, where the antimigraine compound is zolmitriptan, the dose form comprises less than 1 mg of zolmitriptan. Preferably, the dose form comprises less than 0.75 mg of zolmitriptan. More preferably, the dose form comprises less than 0.5 mg of zolmitriptan.
Typically, the dose form further comprises less than 90 percent by weight of water. Preferably, the dose form further comprises less than 80 percent by weight of water. More preferably, the dose form further comprises less than 70 percent, 60 percent, 50 percent, 40 percent, 30 percent, 20 percent, or 10 percent by weight of water.
Typically, the dose form further comprises less than 90 percent by weight of a pharmaceutically acceptable excipient. Preferably, the dose form further comprises less than 80 percent by weight of a pharmaceutically acceptable excipient. More preferably, the dose form further comprises less than 70 percent, 60 percent, 50 percent, 40 percent, 30 percent, 20 percent, or 10 percent by weight of a pharmaceutically acceptable excipient.
In a method aspect of the present invention, either rizatriptan or zolmitriptan is delivered to a mammal through an inhalation route. The method comprises: a) heating a composition, wherein the composition comprises at least 5 percent by weight of rizatriptan or zolmitriptan, to form a vapor; and, b) allowing the vapor to cool, thereby forming a condensation aerosol comprising particles, which is inhaled by the mammal. Preferably, the composition that is heated comprises at least 10 percent by weight of rizatriptan or zolmitriptan. More preferably, the composition comprises at least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90 percent, 95 percent, 97 percent, 99 percent, 99.5 percent, 99.9 percent or 99.97 percent by weight of rizatriptan or zolmitriptan.
Typically, the particles comprise at least 5 percent by weight of rizatriptan or zolmitriptan. Preferably, the particles comprise at least 10 percent by weight of rizatriptan or zolmitriptan. More preferably, the particles comprise at least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90 percent, 95 percent, 97 percent, 99 percent, 99.5 percent, 99.9 percent or 99.97 percent by weight of rizatritpan or zolmitriptan.
Typically, the aerosol has a mass of at least 10 xcexcg. Preferably, the aerosol has a mass of at least 100 xcexcg. More preferably, the aerosol has a mass of at least 200 xcexcg.
Typically, the particles comprise less than 10 percent by weight of rizatriptan or zolmitriptan degradation products. Preferably, the particles comprise less than 5 percent by weight of rizatriptan or zolmitriptan degradation products. More preferably, the particles comprise 2.5, 1, 0.5, 0.1 or 0.03 percent by weight of rizatriptan or zolmitriptan degradation products.
Typically, the particles comprise less than 90 percent by weight of water. Preferably, the particles comprise less than 80 percent by weight of water. More preferably, the particles comprise less than 70 percent, 60 percent, 50 percent, 40 percent, 30 percent, 20 percent, 10 percent, or 5 percent water.
Typically, at least 50 percent by weight of the aerosol is amorphous in form, wherein crystalline forms make up less than 50 percent by weight of the total aerosol weight, regardless of the nature of individual particles. Preferably, at least 75 percent by weight of the aerosol is amorphous in form. More preferably, at least 90 percent by weight of the aerosol is amorphous in form.
Typically, where the particles comprise rizatriptan, the particles comprise less than 5 percent by weight of rizatriptan N-oxide (C15H19N5O, MW of 285.34). Preferably, the particles comprise less than 2.5 percent by weight of rizatriptan N-oxide. More preferably, the particles comprise less than 1, 0.5, 0.1 or 0.03 percent by weight of rizatriptan N-oxide.
Typically, where the particles comprise rizatriptan, the particles comprise less than 5 percent by weight of didehydro rizatriptan (removal of H2, C15H17N5, MW of 267.33). Preferably, the particles comprise less than 2.5 percent by weight of didehydro rizatriptan. More preferably, the particles comprise less than 1, 0.5, 0.1 or 0.03 percent by weight of didehydro rizatriptan.
Typically, where the particles comprise zolmitriptan, the particles comprise less than 5 percent by weight of zolmitriptan N-oxide. Preferably, the particles comprise less than 2.5 percent by weight of zolmitriptan N-oxide. More preferably, the particles comprise less than 1, 0.5, 0.1 or 0.03 percent by weight of zolmitriptan N-oxide.
Typically, where the particles comprise zolmitriptan, the particles comprise less than 5 percent by weight of didehydro zolmitriptan. Preferably, the particles comprise less than 2.5 percent by weight of didehydro zolmitriptan. More preferably, the particles comprise less than 1, 0.5, 0.1 or 0.03 percent by weight of didehydro zolmitriptan.
Typically, the particles of the delivered condensation aerosol have a mass median aerodynamic diameter of less than 5 microns. Preferably, the particles have a mass median aerodynamic diameter of less than 3 microns. More preferably, the particles have a mass median aerodynamic diameter of less than 2 or 1 micron(s).
Typically, the geometric standard deviation around the mass median aerodynamic diameter of the aerosol particles is less than 3.5. Preferably, the geometric standard deviation is less than 3.0. More preferably, the geometric standard deviation is less than 2.5 or 2.0.
Typically, the delivered aerosol has an inhaleable aerosol drug mass density of between 0.25 mg/L and 40 mg/L. Preferably, the aerosol has an inhaleable drug mass density of between 0.5 mg/L and 20 mg/L. More preferably, the aerosol has an inhalable drug mass density of between 0.5 mg/L and 10 mg/L.
Typically, the delivered aerosol has an inhalable aerosol particle density greater than 106 particles/mL. Preferably, the aerosol has an inhalable aerosol particle density greater than 107 particles/mL or 108 particles/mL.
Typically, the rate of inhalable aerosol particle formation of the delivered condensation aerosol is greater than 108 particles per second. Preferably, the aerosol is formed at a rate greater than 109 inhaleable particles per second. More preferably, the aerosol is formed at a rate greater than 1010 inhaleable particles per second.
Typically, the delivered condensation aerosol is formed at a rate greater than 0.5 mg/second. Preferably, the aerosol is formed at a rate greater than 0.75 mg/second. More preferably, the aerosol is formed at a rate greater than 1 mg/second, 1.5 mg/second or 2 mg/second.
Typically, where the condensation aerosol comprises rizatriptan, between 1 mg and 20 mg of rizatriptan are delivered to the mammal in a single inspiration. Preferably, between 1.5 mg and 15 mg of rizatriptan are delivered to the mammal in a single inspiration. More preferably, between 2 mg and 10 mg of rizatriptan are delivered to the mammal in a single inspiration.
Typically, where the condensation aerosol comprises zolmitriptan, between 0.5 mg and 10 mg of zolmitriptan are delivered to the mammal in a single inspiration. Preferably, between 1.5 mg and 7.5 mg of zolmitriptan are delivered to the mammal in a single inspiration. More preferably, between 2 mg and 5 mg of zolmitriptan are delivered to the mammal in a single inspiration.
Typically, the delivered condensation aerosol results in a peak plasma concentration of rizatriptan or zolmitriptan in the mammal in less than 1 h. Preferably, the peak plasma concentration is reached in less than 0.5 h. More preferably, the peak plasma concentration is reached in less than 0.2, 0.1, 0.05, 0.02, 0.01, or 0.005 h (arterial measurement).
Typically, the delivered condensation aerosol is used to treat migraine.
Typically, where the condensation aerosol comprises rizatriptan, less than 4 mg of rizatriptan is inhaled by the mammal in a 2 hour period. Preferably, less than 3.5 mg of rizatriptan is inhaled by the mammal in a 2 hour period. More preferably, less than 3.0 or 2.5 mg of rizatriptan is inhaled by the mammal in a 2 hour period.
Typically, where the condensation aerosol comprises zolmitriptan, less than 1 mg of zolmitriptan is inhaled by the mammal in a 2 hour period. Preferably, less than 0.75 mg of zolmitriptan is inhaled by the mammal in a 2 hour period. More preferably, less than 0.5 mg of zolmitriptan is inhaled by the mammal in a 2 hour period.
In another method aspect of the present invention, a method of treating migraine is provided which comprises administering a dose of an antimigraine compound to a mammal that is less than the typical oral dose.
Typically, where the antimigraine compound is rizatriptan, less than 4 mg of rizatriptan is administered to the mammal in any 2 hour period. Preferably, less than 3.5 mg of rizatriptan is administered to the mammal in any 2 hour period. More preferably, less than 3.0 mg or 2.5 mg of rizatriptan is administered to the mammal in any 2 hour period.
Typically, where the antimigraine compound is zolmitriptan, less than 1 mg of zolmitriptan is administered to the mammal in any 2 hour period. Preferably, less than 0.75 mg of zolmitriptan is administered to the mammal in any 2 hour period. More preferably, less than 0.5 mg of zolmitriptan is administered to the mammal in any 2 hour period.
In a kit aspect of the present invention, a kit for delivering rizatriptan or zolmitriptan through an inhalation route to a mammal is provided which comprises: a) a composition comprising at least 5 percent by weight of rizatriptan and zolmitriptan; and, b) a device that forms a rizatriptan or zolmitriptan aerosol from the composition, for inhalation by the mammal. Preferably, the composition comprises at least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90 percent, 95 percent, 97 percent, 99 percent, 99.5 percent, 99.9 percent or 99.97 percent by weight of rizatriptan or zolmitriptan.
Typically, the device contained in the kit comprises: a) an element for heating the rizatriptan or zolmitriptan composition to form a vapor; b) an element allowing the vapor to cool to form an aerosol; and, c) an element permitting the mammal to inhale the aerosol.
Typically, where the kit comprises rizatriptan, it comprises less than 4 mg of rizatriptan. Preferably, the kit comprises less than 3.5 mg of rizatriptan. More preferably, it comprises less than 3 mg or 2.5 mg of rizatriptan.
Typically, where the kit comprises zolmitriptan, it comprises less than 1 mg of zolmitriptan. Preferably, the kit comprises less than 0.75 mg of zolmitriptan. More preferably, it comprises less than 0.5 mg of zolmitriptan.